Update docs

README.md

@@ -170,7 +170,7 @@ RUSTFLAGS="--cfg portable_atomic_no_outline_atomics" cargo ...
   If dynamic dispatching by run-time CPU feature detection is enabled, it allows maintaining support for older CPUs while using features that are not supported on older CPUs, such as CMPXCHG16B (x86_64) and FEAT_LSE/FEAT_LSE2 (AArch64).
 
   Note:
-  - Dynamic detection is currently only supported in x86_64, AArch64, RISC-V (disabled by default on RISC-V), Arm64EC, and powerpc64, otherwise it works the same as when this cfg is set.
+  - Dynamic detection is currently only supported in x86_64, AArch64, Arm, RISC-V (disabled by default), Arm64EC, and powerpc64, otherwise it works the same as when this cfg is set.
   - If the required target features are enabled at compile-time, the atomic operations are inlined.
   - This is compatible with no-std (as with all features except `std`).
   - On some targets, run-time detection is disabled by default mainly for incomplete build environments, and can be enabled by `--cfg portable_atomic_outline_atomics`. (When both cfg are enabled, `*_no_*` cfg is preferred.)

src/imp/atomic128/README.md

@@ -8,10 +8,10 @@ Here is the table of targets that support 128-bit atomics and the instructions u
 
 | target_arch | load | store | CAS | RMW | note |
 | ----------- | ---- | ----- | --- | --- | ---- |
-| x86_64 | cmpxchg16b or vmovdqa | cmpxchg16b or vmovdqa | cmpxchg16b | cmpxchg16b | cmpxchg16b target feature required. vmovdqa requires Intel, AMD, or Zhaoxin CPU with AVX. <br> Both compile-time and run-time detection are supported for cmpxchg16b. vmovdqa is currently run-time detection only. <br> Requires rustc 1.59+ |
-| aarch64/arm64ec | ldxp/stxp or casp or ldp/ldiapp | ldxp/stxp or casp or stp/stilp/swpp | ldxp/stxp or casp | ldxp/stxp or casp/swpp/ldclrp/ldsetp | casp requires lse target feature, ldp/stp requires lse2 target feature, ldiapp/stilp requires lse2 and rcpc3 target features, swpp/ldclrp/ldsetp requires lse128 target feature. <br> Both compile-time and run-time detection are supported. <br> Requires rustc 1.59+ (aarch64) / 1.84+ (arm64ec) |
-| riscv64 | amocas.q | amocas.q | amocas.q | amocas.q | Experimental because LLVM marking the corresponding target feature as experimental. Requires experimental-zacas target feature. Both compile-time and run-time detection are supported (run-time detection is currently disabled by default). <br> Requires rustc 1.59+ |
-| powerpc64 | lq | stq | lqarx/stqcx. | lqarx/stqcx. | Requires target-cpu pwr8+ (powerpc64le is pwr8 by default). Both compile-time and run-time detection are supported. <br> Requires nightly |
+| x86_64 | cmpxchg16b or vmovdqa | cmpxchg16b or vmovdqa | cmpxchg16b | cmpxchg16b | Requires `cmpxchg16b` target feature (enabled by default on Apple and Windows (except Windows 7) targets). vmovdqa requires Intel, AMD, or Zhaoxin CPU with AVX. <br> Both compile-time and run-time detection are supported for cmpxchg16b. vmovdqa is currently run-time detection only. <br> Requires rustc 1.59+ |
+| aarch64/arm64ec | ldxp/stxp or casp or ldp/ldiapp | ldxp/stxp or casp or stp/stilp/swpp | ldxp/stxp or casp | ldxp/stxp or casp/swpp/ldclrp/ldsetp | casp requires `lse` target feature, ldp/stp requires `lse2` target feature, ldiapp/stilp requires `lse2` and `rcpc3` target features, swpp/ldclrp/ldsetp requires `lse128` target feature. <br> Both compile-time and run-time detection are supported. <br> Requires rustc 1.59+ (aarch64) / 1.84+ (arm64ec) |
+| riscv64 | amocas.q | amocas.q | amocas.q | amocas.q | Experimental because LLVM marking the corresponding target feature as experimental. Requires `experimental-zacas` target feature. Both compile-time and run-time detection are supported (run-time detection is currently disabled by default). <br> Requires rustc 1.59+ |
+| powerpc64 | lq | stq | lqarx/stqcx. | lqarx/stqcx. | Requires `quadword-atomics` target feature (enabled by default on powerpc64le). Both compile-time and run-time detection are supported. <br> Requires nightly |
 | s390x | lpq | stpq | cdsg | cdsg | Requires rustc 1.84+ |
 
 On compiler versions or platforms where these are not supported, the fallback implementation is used.

src/imp/atomic128/intrinsics.rs

@@ -16,7 +16,7 @@ implementation with inline assembly.
 
 Note:
 - This currently needs Rust 1.70 on x86_64, otherwise nightly compilers.
-- On powerpc64, this requires LLVM 15+ and pwr8+ (quadword-atomics LLVM target feature):
+- On powerpc64, this requires LLVM 15+ and quadword-atomics target feature:
   https://github.com/llvm/llvm-project/commit/549e118e93c666914a1045fde38a2cac33e1e445
 - On s390x, old LLVM (pre-18) generates libcalls for operations other than load/store/cmpxchg:
   https://github.com/llvm/llvm-project/commit/c568927f3e2e7d9804ea74ecbf11c16c014ddcbc

src/imp/atomic64/README.md

@@ -10,7 +10,7 @@ Here is the table of targets that support 64-bit atomics and the instructions us
 | ----------- | ---- | ----- | --- | --- | ---- |
 | x86 | cmpxchg8b or fild or movlps or movq | cmpxchg8b or fistp or movlps | cmpxchg8b | cmpxchg8b | provided by `core::sync::atomic` |
 | arm | ldrexd | ldrexd/strexd | ldrexd/strexd | ldrexd/strexd | provided by `core::sync::atomic` for Armv6+, otherwise provided by us for Linux/Android using kuser_cmpxchg64 (see [arm_linux.rs](arm_linux.rs) for more) |
-| riscv32 | amocas.d | amocas.d | amocas.d | amocas.d | Experimental because LLVM marking the corresponding target feature as experimental. Requires experimental-zacas target feature. Both compile-time and run-time detection are supported (run-time detection is currently disabled by default). <br> Requires rustc 1.59+ |
+| riscv32 | amocas.d | amocas.d | amocas.d | amocas.d | Experimental because LLVM marking the corresponding target feature as experimental. Requires `experimental-zacas` target feature. Both compile-time and run-time detection are supported (run-time detection is currently disabled by default). <br> Requires rustc 1.59+ |
 
 If `core::sync::atomic` provides 64-bit atomics, we use them.
 On compiler versions or platforms where these are not supported, the fallback implementation is used.

src/lib.rs

@@ -164,7 +164,7 @@ RUSTFLAGS="--cfg portable_atomic_no_outline_atomics" cargo ...
   If dynamic dispatching by run-time CPU feature detection is enabled, it allows maintaining support for older CPUs while using features that are not supported on older CPUs, such as CMPXCHG16B (x86_64) and FEAT_LSE/FEAT_LSE2 (AArch64).
 
   Note:
-  - Dynamic detection is currently only supported in x86_64, AArch64, RISC-V (disabled by default on RISC-V), Arm64EC, and powerpc64, otherwise it works the same as when this cfg is set.
+  - Dynamic detection is currently only supported in x86_64, AArch64, Arm, RISC-V (disabled by default), Arm64EC, and powerpc64, otherwise it works the same as when this cfg is set.
   - If the required target features are enabled at compile-time, the atomic operations are inlined.
   - This is compatible with no-std (as with all features except `std`).
   - On some targets, run-time detection is disabled by default mainly for incomplete build environments, and can be enabled by `--cfg portable_atomic_outline_atomics`. (When both cfg are enabled, `*_no_*` cfg is preferred.)